BepiColombo launch rescheduled for October 2018

An ambitious, multi-spacecraft mission to explore the planet Mercury in unprecedented detail is now scheduled for lift-off from Europe's spaceport at Kourou, French Guiana, in October 2018.

BepiColombo, a joint project of ESA and the Japan Aerospace Exploration Agency (JAXA), was scheduled for launch in April 2018, but the mission team has decided to delay lift-off for six months.

The decision was made after a major electrical problem was detected during preparations for a thermal test of the Mercury Transfer Module (MTM), one of the major spacecraft elements of BepiColombo.

"Launch during the April 2018 window will not be possible, due to a problem in one of the power processing units," said ESA's project manager, Ulrich Reininghaus. "We have identified the root cause, but both units will have to be recertified for flight and this is expected to put back our preparations by about four months. This means the earliest opportunity to launch will be October 2018."

The six-month postponement will have no impact on the science return of the mission. However, the new flight time to Mercury will be 7.2 years, and BepiColombo will now arrive in December 2025, one year later than previously anticipated. The seven-year cruise to the innermost planet of our Solar System will include 9 flybys of Earth, Venus and Mercury.

"Unfortunately, we will have to wait longer than planned to reach Mercury," said Johannes Benkhoff, ESA's BepiColombo project scientist. "However, we have full confidence that the mission will be a success and return groundbreaking results."

BepiColombo comprises two scientific spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). Both of these will be delivered to the smallest planet in the Solar System by the Mercury Transfer Module (MTM). Shortly before Mercury orbit insertion, the MTM will be jettisoned from the spacecraft stack.

The MTM, MPO and MMO are currently undergoing intensive tests in ESA's European Space Research and Technology Centre (ESTEC) in the Netherlands. Everything is going well with the MPO and MMO. The last of the instrument flight models was installed recently on the MPO.

Once the MTM is back on track, the entire BepiColombo stack will be subjected to vibration testing – expected in April next year.